In road speed control and engine governors for vehicles, it is common practice to utilize a lost motion linkage in coupling the accelerator with the throttle control member and with an overriding throttle closing member of the governor. In general, the accelerator is coupled through a spring loaded lost motion device to the throttle control member, i.e. the throttle control arm of a carburetor or an injector control arm of a fuel injection system. The governor has an overriding throttle closing member which, when activated, is held at a throttle limiting position and is coupled to the throttle control member to prevent throttle opening beyond the limiting position. The spring loaded lost motion device is effective to couple the throttle control member with the accelerator so that it moves concurrently therewith until the throttle limiting position is reached and then further movement of the accelerator is taken up by the lost motion spring while the throttle control member is held fixed. Devices of this type are known in the prior art patents.
The Pitchford U.S. Pat. No. 3,604,404 granted Sept. 14, 1971, discloses a vehicle speed control system in which the accelerator is coupled through a throttle rod and a spring loaded lost motion device to the throttle arm of the carburetor. The lost motion device comprises a tubular housing which is connected at one end with the throttle rod. The housing contains a movable member which is connected by a ball stud with the throttle arm and which is spring biased by a compression spring in the housing. A speed control unit which is adapted to establish a throttle limiting position is coupled with the slidable member by a flexible cable, the sheath of which is attached to the other end of the housing.
The Krueger et al U.S. Pat. No. 4,362,138 granted Dec. 7, 1982, discloses a vehicle governor throttle linkage including a lost motion device. In this arrangement, the accelerator is connected through a throttle rod to one end of a tubular housing which contains a movable member coupled by a ball stud with the throttle arm of the carburetor. The movable member is spring biased by a spring which is disposed between the other end of the housing and the movable member. The governor has an overriding throttle closing member which is connected through a flexible cable to the ball stud.
The Marie U.S. Pat. No. 3,547,216 granted Dec. 15, 1970, discloses a top speed limiting device for vehicles with a lost motion device between the accelerator and the throttle arm. In this system, a fixed shaft is mounted in the housing of the governor and a connecting disk is mounted on a hub portion around the shaft. The connecting disk is connected through a link with the throttle valve of the carburetor. An accelerator actuated member having an integral hub portion is rotatably mounted on the stationary shaft outwardly of the connecting disk. A torsional spring is connected between the accelerator actuated member and a connecting disk to provide spring loaded lost motion therebetween. The hub portion of the connecting disk carries a stop tab which engages a stop limiting member movable to a throttle limiting position by the governor.
The prior art devices are not well adapted for installing a governor on an engine having, prior to governor installation, a driver operated accelerator coupled by a flexible cable to a throttle control member of the engine.
A general object of this invention is to provide a dual cable lost motion coupling for the throttle linkage of an engine governors which overcomes certain disadvantages of the prior art.